So-called split-apart basket stretchers are known in the prior art. These conventional forms of basket stretchers are modular in the sense that the basket stretcher may be broken apart or formed as hinged sections for ease of transport. Conventionally, such basket stretchers have longitudinally extending rigid rails. In the prior art, the opposed facing ends of the rails at the juncture between the sections of the split-apart basket stretcher, are releasably coupled to one another by a threaded sleeve or collar on one of the opposed facing ends of each rail threadably mounting onto threads on the other opposed facing ends of the rails. Such a sleeve or collar is referred to in the trade as a collet.
The two conventional sections of the basket stretcher are connected by spinning or screwing the collet into threaded engagement with the opposite rail ends of the opposite section of the basket stretcher. However, it has been observed that such collets once threaded into place, may become unthreaded so as to dangerously allow the sections of the basket stretcher to disconnect, while the basket stretcher is being raised or lowered so as to bump or scrape against rocks, a cliff face, the outer wall of a building etc. during use. Consequently, there exists a need, and is an object of the present invention to provide, a releasable locking mechanism which prevents the collets from inadvertently unscrewing from threaded engagement on the opposed end of the basket stretcher rail so as to no longer merely rely on the diligence of the operators to observe that the collet remains fully threaded into place. It is a further object to provide that the operators may, as before, simply screw the collet into locking engagement as in the prior art and that the locking mechanism according to the present invention not disturb the conventional threaded engagement of the collet.
Further in the prior art, applicant is aware of U.S. Pat. No. 2,843,408 which issued on Jul. 15, 1958 to Stukenborg for a Lock for Turnbuckles, U.S. Pat. No. 3,073,635 which issued Jan. 15, 1963 to Schaefer for a Shaft Coupling, U.S. Pat. No. 3,682,506 which issued Aug. 8, 1972 to Bruyere et al. for Coupling Devices and U.S. Pat. No. 6,328,499 which issued Dec. 11, 2001 to Reding et al. for a Screwed Connection for Threaded Rods. None of the prior art of which applicant is aware teach nor suggest the use of a releasable pin locking mechanism, whether resiliently biased or not, which pin locking mechanism engages behind the trailing face of the collet when in threaded engagement over the opposed rail end so as to prevent the collet unscrewing until the pin locking mechanism is depressed, removed or otherwise disengaged from preventing the rearward translation of the collet.
It is yet a further object to provide a locking mechanism, whether using a pin or other stop, for preventing the rearward translation of the collet wherein the pin mechanism does not protrude beyond the outer surface of the collet so that the trailing edge of the collet protects the stop mechanism from impacting an external rigid surface over which the basket stretcher is being bumped or dragged.